Car running too hot, gas mileage?

[denverAlero99]

I have a 99 3.4 Alero (~95k miles). I'm not sure what the root of my problem is so I will tell you what I do know.

Maybe 3 weeks ago I noticed steam coming from the engine (my temp gauge started to rise too). I immediately pulled over (the temp gauge was between the 2/3 and 3/4 mark), popped the hood and noticed the steam was coming from the coolant overflow tube. Opening the reservoir, it was obvious that the coolant was too hot and too low. It was the coolant that was steaming, not the engine. I don't think any damage was done to the engine. The coolant overheated before the engine did and I didn't drive it while it was hot. I had checked the coolant level a week or so before so I assumed/knew I must have lost coolant due to a leak. I had checked it because the temp gauge was slightly rising when sitting in traffic and driving uphill (then droping to normal - 1/2 mark - when driving in normal -flat, not idling - conditions). So I added coolant [DEXCOOL] and was able to make it home (not far - no problems). When I got home, it was obvious that the water pump was leaking the coolant. I had the water pump replaced and my coolant problem was 'solved'.

When the mechanic [who replaced the water pump] was checking the car, he noticed a small pool of coolant under the air intake on the driver's side. The oil was not milky so the problem was caught early enough (I think). The mechanic replaced the LIM gasket and said the car was in 'great shape'. However, after driving my car for a couple of days it smelled like coolant. At first, I thought this was coolant 'burning off' (coolant had dripped on to the serpentine belt and was then 'flung' all over the car while it was running). After a couple of days though, the smell had not gone away (no longer leaking coolant, not overheating). The car seemed to be running mostly fine. I say mostly fine because outside of the coolant smell, the temp gauge would rise slightly (going uphill or sitting in traffic) and the gas mileage started to taper off. Performance, idling, starting, etc is fine though. I take it back in to the mechanic and tell him about the smell. They seem to think that maybe the car is leaking coolant. They check the car 'from top to bottom' but find no leaks (pressure tested). I was also told that they checked it for any codes in the computer but nothing came up. They also said they checked the O2 sensor but that it was operating properly. They assure me that the car is in great shape, steam clean the engine (they thought it was coolant burning off), and tell me maybe I had a bad tank of gas (I know that is not the case as my wife's car is running fine on the same gas - I fill them up at the same time).

I don't know much about car repair but I know that my car did not run as hot as it does now, it did not used to smell like burnt coolant and I used to get 27.5 - 29/mpg. Overnight the gas mileage went down by maybe 20% and when I say the car is running hot, I mean you don't even have to open the hood to realize that it is too hot. Even though the temp gauge sits in the middle and it gets up to temp quickly, I know that it is too hot. I believe that the burnt coolant smell, temp increasing while sitting traffic/going uphill, and the hot engine are all related. I'm not sure what the problem is though. There is a new water pump, the hoses are fine and are in good condition, new thermostat, and the coolant has been flushed within the last year and a half. I flushed the coolant for the first time at 5 years/85k.

I'm not sure if the water pump/LIM gasket are even related to my two current problems (running hot, gas mileage) but I thought I should mention them. It is my understanding that in order to replace the LIM gaskets you have to remove the fuel lines from the gas tank (upper intake). Could this affect my mileage or is it something else? I have checked the obvious: tire pressure, fuel filter, air filter, etc. but I don't think such things could contribute to such a drastic loss in gas mileage overnight. Could fuel injection be the culprit for the decrease in gas mileage? Other? I have no idea why the engine is running so hot? Fans? Radiator? Any ideas would be helpful. Recomendations on a mechanic in the Denver, CO area? Thanks!

[vamc]

This seems to be that nasty headgasket problem. I have a 99 alero with the 3.4 engine with 135,500mi on it. I had mine replased last year. I will takl to my friend on here, and see if i can get his thought on this.

[denverAlero99]

What makes you think it's the head gasket? I was under the impression that the car would be running very poorly if it was the head gasket. My 'knowledge' comes from reading about 10/15 pages of posts on the alero on this board. The car is running very well. I haven't noticed any changes in how it drives. I'm just curious as to what tipped you off in my previous post that made you think it was the head gasket. Approx. how much was it to have it fixed?

Thanks again.

[JTrujillo86]

If you plan on taking your car to a dealership, I recommend McCaddon Oldsmobile in Boulder on Pearl Pkwy. or Century Chevrolet in Broomfield on
120th and Sheridan.

- Jeremy

[vamc]

Well i had the same problem you were having. I have helped meny people out with this issue, and it was solved. Bayliner(Bob) has had this same problem as well i beleve, could be wrong though, WE, Bob and myself have people out with kind of issue. He is on the Grand prix fourms and Alero fourms. Ask him for this thoughts as well.

[MagicalAnimal]

My car, a 2000 V6, just started doing ALL of the same things as yours. The only thing mine is doing that you didn't mention is that when I turn my heat on, the air is cold, unless I am driving.. as soon as I stop, the heat starts coming out cold. It's very odd but I think it's somehow tied in since it all just started happening within the past few days-week (at first I just ignored it, but now think it's an issue) I think the first thing I noticed was the car smelled "hot" and almost like hot windex.. just today I noticed the temperature gauge rising while idling, going up hill because I started my car this morning and let her run for a while to warm up and when I came out side it sounded louder than normal and when I got near I noticed the fan was running and when I got in the temp gauge was up to the 3... I started driving though and once I got moving it went back down to the half mark, where it normally is. I don't know what this problem is but I JUST got my car fixed a week ago! I had a bad wheel bearing and just paid 200 to get it fixed.. if this is something major I am going to be super mad! Someone help, let us know what the problem is

[vamc]

Head gasket leak or thurmastat.

[patricia40]

The only thing I can do is give you my tale of woe that should make you feel better. Took my piece of crap '00 Alero to the dealer on Thurs because my ABS, Service Engine, and Trac Off lights were on. Here's list list of things that needed to be replaced: Both upper strut bearings,right front outer tie rod, left lower control arm bushing, wheel bearing , wheel bearing harness, all of the lower intake manifold gaskets which were leaking coolant into the engine which then needed to be flushed, new wires and plugs, pcv valve, coolant replaced, and 4 wheel alignment. Final tally $3945.81(canadian) I asked if Chip Foose was there and had I perhaps been overhauled. $1653 in parts, $1777 in labour. I called GM to see if there were any secret recalls, they said no. They were no help at all. I am super peeved!!! T

[vamc]

pcv valve. do do know if it was bad? If you shake it and hear a noice, its good. The head gasket stuff should cause you about 4-6 hundred dollars or so. If you see chip foose, tell him to stop over here.

[MagicalAnimal]

Originally Posted by MagicalAnimal

My car, a 2000 V6, just started doing ALL of the same things as yours. The only thing mine is doing that you didn't mention is that when I turn my heat on, the air is cold, unless I am driving.. as soon as I stop, the heat starts coming out cold. It's very odd but I think it's somehow tied in since it all just started happening within the past few days-week (at first I just ignored it, but now think it's an issue) I think the first thing I noticed was the car smelled "hot" and almost like hot windex.. just today I noticed the temperature gauge rising while idling, going up hill because I started my car this morning and let her run for a while to warm up and when I came out side it sounded louder than normal and when I got near I noticed the fan was running and when I got in the temp gauge was up to the 3... I started driving though and once I got moving it went back down to the half mark, where it normally is. I don't know what this problem is but I JUST got my car fixed a week ago! I had a bad wheel bearing and just paid 200 to get it fixed.. if this is something major I am going to be super mad! Someone help, let us know what the problem is

OK.. so.. update. I checked my coolant and the coolant was low (figured as much, just couldn't do anything about it the other night) so I added some coolant, it took about 1/2 the container (gallon maybe?) and then I drove it all the way home from where I was (about 25 miles, mostly highway) and she worked just fine. Didn't heat up too fast, never got too hot, didn't smell bad at all... even as a test, when I got in the drive way I just sat there with it running and the temp gauge never went above the 1/2 way mark at all. Ya think I still have something really wrong? I know for a fact one of my hoses that holds the coolant has a leak, discovered that when we replaced the water pump a few years back, but the mechanic said it was more of a pain to fix than to just add coolant every now and then. I don't normally check my coolant or add to it because they do it when I get my oil changed, which was only about 3 weeks ago, but it's VERY possible they just didn't top it off last time I was there (they were kinda in a rush) and it leaked out and got low. If I watch it closely and all the bad stuff doesn't happen anymore ya think I'll be OK? I really cant afford another huge repair bill right now and if Im Ok to drive it like this for a while until I really can afford it, that would be great

[patricia40]

The only thing I can tell you that happened to me was, my coolant light came on, checked it, it was low topped it up a couple of days later it was low again. Couldn't figure it out. At the dealership they discovered a misfire once they hooked it up to their computer ( I couldn't tell, seemed to run fine).
Turns out all the lower intake gaskets were shot. Thats where my coolant went. Then of course the injectors needed to be flushed, cooling system flushed new plugs and wires. CHACHING. Hope this isn't same for you.
T

[vamc]

The intake gasket is the norm for the 4 cil and the 3.4 engines. nothing new on that issue.